Add eth proof generation utilities

eth2near/Cargo.toml

@@ -7,6 +7,7 @@ members = [
     "eth_rpc_client",
     "finality-update-verify",
     "logger",
+    "utilities",
 ]
 
 [workspace.dependencies]

eth2near/utilities/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "utilities"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+reqwest = { version = "0.11", features = ["blocking", "json"] }
+serde_json = "1.0.74"
+serde = { version = "1.0", features = ["derive"] }
+hex = { version="0.4", features = ["serde"] }
+num-traits = "0.2"
+cita_trie = "5.0.1"
+hasher = "0.1.4"
+rlp = "0.5.2"

eth2near/utilities/src/eth_proof_generator.rs

@@ -0,0 +1,166 @@
+use crate::{
+    eth_rpc_client::EthRPCClient,
+    primitives::*,
+    types::{BlockHeader, Log, TransactionReceipt},
+};
+use cita_trie::{MemoryDB, PatriciaTrie, Trie, TrieError};
+use hasher::HasherKeccak;
+use rlp::RlpStream;
+use std::error::Error;
+use std::sync::Arc;
+
+#[derive(Debug)]
+pub struct Proof {
+    pub log_index: u64,
+    pub log_entry_data: Vec<u8>,
+    pub receipt_index: u64,
+    pub receipt_data: Vec<u8>,
+    pub header_data: Vec<u8>,
+    pub proof: Vec<Vec<u8>>,
+}
+
+pub fn get_proof_for_event(tx_hash: &str, log_index: u64, node_url: &str,) -> Result<Proof, Box<dyn Error>> {
+    let client = EthRPCClient::new(node_url);
+
+    let tx_bytes: [u8; 32] = hex::decode(&tx_hash[2..])?
+        .try_into()
+        .map_err(|_| Box::<dyn Error>::from("Invalid hex string length"))?;
+
+    let receipt = client.get_transaction_receipt_by_hash(&FixedBytes(tx_bytes))?;
+    let block_header = client.get_block_by_number(receipt.block_number)?;
+    let block_receipts = client.get_block_receipts(receipt.block_number)?;
+
+    let trie = build_receipt_trie(&block_receipts)?;
+
+    let receipt_key = rlp::encode(&receipt.transaction_index);
+    let proof = trie.get_proof(&receipt_key)?;
+
+    let mut log_data: Option<Vec<u8>> = None;
+    for log in &receipt.logs {
+        if log.log_index == log_index {
+            log_data = Some(encode_log(log));
+        }
+    }
+
+    Ok(Proof {
+        log_index,
+        log_entry_data: log_data.ok_or("Log not found")?,
+        receipt_index: receipt.transaction_index,
+        receipt_data: encode_receipt(&receipt),
+        header_data: encode_header(&block_header),
+        proof,
+    })
+}
+
+fn build_receipt_trie(receipts: &[TransactionReceipt],) -> Result<PatriciaTrie<MemoryDB, HasherKeccak>, TrieError> {
+    let memdb = Arc::new(MemoryDB::new(true));
+    let hasher = Arc::new(HasherKeccak::new());
+    let mut trie = PatriciaTrie::new(memdb, hasher);
+
+    for receipt in receipts {
+        let receipt_key = rlp::encode(&receipt.transaction_index).to_vec();
+        let receipt_data = encode_receipt(receipt);
+
+        trie.insert(receipt_key, receipt_data)?;
+    }
+
+    Ok(trie)
+}
+
+fn encode_receipt(receipt: &TransactionReceipt) -> Vec<u8> {
+    let mut stream = RlpStream::new();
+
+    if receipt.transaction_type != 0 {
+        stream.append(&receipt.transaction_type);
+    }
+
+    stream.begin_list(4);
+    stream
+        .append(&receipt.status)
+        .append(&receipt.cumulative_gas_used.0)
+        .append(&receipt.logs_bloom.0.as_slice());
+
+    stream.begin_list(receipt.logs.len());
+    for log in &receipt.logs {
+        stream.begin_list(3);
+        stream.append(&log.address.0.as_slice());
+
+        stream.begin_list(log.topics.len());
+        for topic in &log.topics {
+            stream.append(&topic.0.as_slice());
+        }
+
+        stream.append(&log.data.0);
+    }
+
+    stream.out().to_vec()
+}
+
+fn encode_log(log: &Log) -> Vec<u8> {
+    let mut stream = RlpStream::new();
+    stream.begin_list(3);
+
+    stream.append(&log.address.0.as_slice());
+
+    stream.begin_list(log.topics.len());
+    for topic in &log.topics {
+        stream.append(&topic.0.as_slice());
+    }
+
+    stream.append(&log.data.0);
+
+    stream.out().to_vec()
+}
+
+fn encode_header(header: &BlockHeader) -> Vec<u8> {
+    let mut stream = RlpStream::new();
+    stream.begin_unbounded_list();
+
+    stream
+        .append(&header.parent_hash.0.as_slice())
+        .append(&header.sha3_uncles.0.as_slice())
+        .append(&header.miner.0.as_slice())
+        .append(&header.state_root.0.as_slice())
+        .append(&header.transactions_root.0.as_slice())
+        .append(&header.receipts_root.0.as_slice())
+        .append(&header.logs_bloom.0.as_slice())
+        .append(&header.difficulty)
+        .append(&header.number.0)
+        .append(&header.gas_limit.0)
+        .append(&header.gas_used.0)
+        .append(&header.timestamp.0)
+        .append(&header.extra_data.0.as_slice())
+        .append(&header.mix_hash.0.as_slice())
+        .append(&header.nonce.0.as_slice());
+
+    header.base_fee_per_gas.map(|v| stream.append(&v));
+    header.withdrawals_root
+        .as_ref()
+        .map(|v| stream.append(&v.0.as_slice()));
+    header.blob_gas_used.map(|v| stream.append(&v));
+    header.excess_blob_gas.map(|v| stream.append(&v));
+    header.parent_beacon_block_root
+        .as_ref()
+        .map(|v| stream.append(&v.0.as_slice()));
+
+    stream.finalize_unbounded_list();
+    stream.out().to_vec()
+}
+
+#[cfg(test)]
+pub mod tests {
+    use super::*;
+    use hasher::Hasher;
+
+    #[test]
+    fn generate_proof() {
+        const RPC_URL: &'static str = "https://eth.llamarpc.com";
+        const TX_HASH: &'static str = "0x9298954a9db8026ca28bce4d71ffb7ba0aac70e91f0667ffb7398c67e60b84fa";
+        let proof = get_proof_for_event(TX_HASH, 377, RPC_URL).unwrap();
+
+        let hasher = HasherKeccak::new();
+
+        println!("Header {:x?}", hasher.digest(&proof.header_data));
+        println!("Proof {:x?}", &proof.proof);
+    }
+}